Re: The fable of DEMETRIUS, CONSTRAINTICUS, and AUTOMATICUS

From: Tony Andrews <andrewst_at_onetel.com>
Date: 19 Oct 2004 09:01:16 -0700
Message-ID: <1098201676.127491.313250_at_c13g2000cwb.googlegroups.com>


Gene Wirchenko wrote:
> "Tony Andrews" <andrewst_at_onetel.com> wrote:
> >Foreign key constraints implement a subset of
> >possible multi-table rules, e.g. "employee.deptno must correspond to
a
> >department.deptno", but not all conceivable constraints, e.g.
> >"employee.deptno must correspond to a department.deptno where
> >employee.hiredate between department.open_date and
> >department.close_date".
>
> All employees for a new department must be newly-hired?

Whatever - it was just to illustrate a complex constraint; maybe I could have done better with more thought. Received on Tue Oct 19 2004 - 18:01:16 CEST

Original text of this message